The invention relates to an independent wheel suspension for non-steered wheels of a motor.
It is known to use a bearing spring and a shock absorber in the case of an independent wheel suspension, the shock absorber being situated between a vehicle-body-fixed support bearing and a control arm of the independent wheel suspension or a wheel carrier. The spring is placed in the inverted position over the shock absorber, the inside diameter of the spring being designed such that, during a deflection, the shock absorber will not come in contact with the interior side of the spring.
When a twin tube shock absorber is used, as a result of the shorter length of the twin tube shock absorber, less space is advantageously required in comparison to a single tube shock absorber. However, the spring which, in the case of the twin tube shock absorber, is arranged at the upper end of the shock absorber, requires a corresponding diameter and therefore more space in the transverse direction of the vehicle. Correspondingly, domes or bulges are constructed in the trunk which limit the load-through width of the motor vehicle trunk.
It is an object of the invention to provide an independent wheel suspension for non-steered wheels of a motor vehicle, in the case of which the load-through width of the motor vehicle trunk is increased.
By adapting, according to the invention, the shape of the space bounded by the spring to the space requirement of the shock absorber during the deflection and the distance of the spring according to the invention to the components surrounding the spring, the size of the spring is reduced such that the space required for the spring is correspondingly smaller.
In another advantageous embodiment, the main swivelling direction of the shock absorber is essentially designed in the transverse direction of the vehicle so that the spring according to the invention takes up relatively little space in the longitudinal direction of the vehicle. In an advantageous embodiment, the spring according to the invention has an elliptical shape in the top view. It is also an advantage that the spring according to the invention has a conical construction.
Advantageously, the spring according to the invention is arranged such at the lower end of the shock absorber that the smaller cross-section of the spring is situated at the lower end of the shock absorber.
A uniform bending or bulging behavior and/or a uniform distribution of the tension of the spring according to the invention is advantageously achieved in that the wire diameter of the spring as well as the pitch of the spring are constructed such on the corresponding areas of the spring that the spring according to the invention has at least approximately a uniform stiffness in the required directions.
As the result of the reduced size of the spring according to the invention as well as the arrangement of the spring at the lower end of the shock absorber, when the spring shock absorber according to the invention is arranged below the trunk floor of a motor vehicle, an enlargement of the load-through width of the motor vehicle trunk is achieved. The widening for one side amounts, for example, to maximally four times the value which is obtained from the sum of the spring wire diameter and of the safety distance between the spring and the shock absorber. According to another method of calculation, the load-through width increases by twice the value from the difference between the inside diameter of the spring, including the safety distance, and the shock absorber diameter.
In an advantageous embodiment, in which the spring shock absorber according to the invention, in the case of a powered axle, is arranged next to the output shaft, the shock absorber can be kinematically integrated such that its main swivelling direction during the deflection extends approximately in parallel to the output shaft or its components, such as an elastomer collar. In this embodiment, by means of an elliptical spring shape according to the invention, the shock absorber can be positioned closer to the output shaft by the amount which is the result of the difference between the small elliptical semiaxis and the large elliptical semiaxis.
By means of the independent wheel suspension according to the invention, a more compact axle package is obtained with a correspondingly smaller space requirement and, as a function of the kinematics, also a larger shock absorber transmission ratio, because the lower end of the shock absorber can be arranged closer to the wheel carrier of a motor vehicle wheel. Because of the maximized shock absorber ratio, the construction according to the invention requires lower forces acting in the independent wheel suspension according to the invention which results in better comfort characteristics.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.